Scrub brush



FIG. 1 is a top plan view of a scrub brush showing our new design;

FIG. 2 is a right side view thereof, the left side view being a mirror image of the right side view;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a bottom plan view thereof; and

FIG. 6 is a bottom plan view analogous to FIG. 5, but with the brush bristles removed. 

The ornamental design for a scrub brush, substantially as shown. 